I'm stumped here. When setting up my mash and sparge water volumes, BTP calculates that I have X amount of collected water, but in reality I have more.

For example, I did a mash with 8.56 pounds of grain. I set mash thickness @ 1.12 qt/lb = 2.39 gallons of water. Sparge water was 2.86, which equals 5.3 gallons of water total. BTP predicted a total of 4.05 gallons collected with 2 pints residual.

In reality, I ended up collecting about 4.6 gallons of water. What when wrong here? I'm I missing something?

Legman wrote:I'm stumped here. When setting up my mash and sparge water volumes, BTP calculates that I have X amount of collected water, but in reality I have more.

For example, I did a mash with 8.56 pounds of grain. I set mash thickness @ 1.12 qt/lb = 2.39 gallons of water. Sparge water was 2.86, which equals 5.3 gallons of water total. BTP predicted a total of 4.05 gallons collected with 2 pints residual.

In reality, I ended up collecting about 4.6 gallons of water. What when wrong here? I'm I missing something?

Sometimes there is confusion over what "residual" is. Residual is available runoff not collected during the sparge. Available runoff is extract that is not absorbed by the grain husks. So, if the tun is drained until there is no more runoff, then residual should be 0 in BTP.

If you drained all of your runoff, then the 2 pints of residual in the mash schedule should actually be 0 to match your process more accurately. To fine tune BTP to come even closer, you can adjust the "malt water absorption" setting in the preferences panel.

I took a look at that and I'm still not quite sure what the heck I'm doing. I'll have to try it on the next batch and see what it does.
I may have been wrong about the 2 pints. I think it's really closer to 1.
I changed the the residual to 0, but there is always some runoff you don't collect.
But I'm still not sure what the number are doing or what the mean yet. I'll figure that out soon, I suppose.

With grain absorption, I've always heard the it's .125 gal. per pound. So what your suggesting is that may not be the case as part of my problem.

There shouldn't be, other than your dead space. Put your dead space in your vessel description, then you can always set your residual volumes to '0'. Any wort you leave behind is a drop in efficiency. You should plan your mashes to drain fully and deliver the pre-boil volume you need.

There shouldn't be, other than your dead space. Put your dead space in your vessel description, then you can always set your residual volumes to '0'. Any wort you leave behind is a drop in efficiency. You should plan your mashes to drain fully and deliver the pre-boil volume you need.

Ah, that's not quite right. With fly sparging there will always be wort/liquid left behind -- or at least their should be, unless you're calculating to the very exact drop how much sparge water you need -- and that's pretty much impossible to do, BTP or no BTP.

just-cj wrote:Ah, that's not quite right. With fly sparging there will always be wort/liquid left behind -- or at least their should be, unless you're calculating to the very exact drop how much sparge water you need -- and that's pretty much impossible to do, BTP or no BTP.

That's correct; with batch sparging, you drain as much of the sparge water as you can, but with fly sparging (at least as I understand it, since I've never done it), you should stop draining as soon as you have your target volume but the grain bed should still be covered with water, right? Since I've never set one up, I have no idea how BTP figures the sparge water for a fly sparge, but I would imagine that might depend a little bit on the dimensions of your tun, wouldn't it? In other words, if your grain bed is deep because you use something like a round cooler, there isn't as much surface area on top to be covered with water, as opposed to using a large rectangular ice chest with a shallow grain bed and a lot of area on top to be covered with water. Not to start an argument about which is best, but I'd encourage any new brewer to at least give batch sparging a try. I get about 80% efficiency, it requires less equipment, it's easier to set up and do, and a lot faster (based on comments from fly sparges compared to my times), and you never need to worry about over-sparging which can collect tannins. Just my two cents.

Well, with fly sparging, you don't have to keep liquid over the grain bed when you get near your target volume, but until the last gallon or so, you do.

As for which is easier, batch or fly, it really depends on the system. In my system, I've tried batch sparging a couple times and it has taken longer due to stuck mashes -- hopelessly stuck mashes. I'd really encourage every new all-grain brewer to try both and make an informed decision about what works best in your system. Of course, if you've set up your system with one or the other in mind, you may have no need or desire to fart around doing things differently -- good! Keep doing what you're doing.

There shouldn't be, other than your dead space. Put your dead space in your vessel description, then you can always set your residual volumes to '0'. Any wort you leave behind is a drop in efficiency. You should plan your mashes to drain fully and deliver the pre-boil volume you need.

Ah, that's not quite right. With fly sparging there will always be wort/liquid left behind -- or at least their should be, unless you're calculating to the very exact drop how much sparge water you need -- and that's pretty much impossible to do, BTP or no BTP.

I just assumed, without thinking, when he said "calculating sparge water volumes", that he was batch sparging (as all right thinking people should, of course ).
Obviously, that isn't necessarily the case, so thanks for clarifying that.
There's always a risk with assumptions.

just-cj wrote:snip ... I'd really encourage every new all-grain brewer to try both and make an informed decision about what works best in your system. Of course, if you've set up your system with one or the other in mind, you may have no need or desire to fart around doing things differently -- good! Keep doing what you're doing.

Well, trying both isn't necessarily the most practical approach to get maximum benefit from either technique. For instance, if a person wants the easiest and cheapest approach, I'd have to say that it is using a bazooka to batch sparge, but a bazooka is undoubtedly the worst configuration for fly sparging because it will most likely cause channelling and your efficiency will suffer. Likewise if you start at the other end and build a properly designed manifold or false bottom; then you will have gone to a lot of extra expense and trouble, compared to making a bazooka, that will accomplish nothing in a batch sparge that a simple bazooka wouldn't do. That being the case, I would suggest that people try batch sparging with a bazooka first, and if they think that they can improve their efficiency, quality of beer, or have more fun fly sparging, then just toss the bazooka in a box to save for some other brewing use (e.g., making a bazooka for a keggle) and start over with a properly designed manifold or false bottom plus a sparging device of some sort. That way you will be out only about $10 to $15 and about 15 minutes of your time; do it the other way and you will probably be out a lot more with no discernable difference in your batch sparge results.

Now, you mentioned a stuck sparge. The closest I've ever come to that just happened a few weeks ago when my grist contained almost half regular baking flour (6 pounds of malted barley and 5 pounds of flour), and no rice hulls, and it drained very slowly -- but never did completely stop. I'm guessing that it probably took maybe 45 minutes for first runnings and batch sparges -- which is a LOT longer than any 9.5 gallons of pre-boil wort has ever taken me. But the nice thing about batch sparging is that I just did other things and checked my bucket periodically, so it didn't tie me down much but rather just delayed the boil and extended my brew day a bit. Not really a big deal. And I'm not convinced that fly sparging would have helped speed up the process, and my efficiency was about 85% (actually, I suspect "flour" needs to be added to the adjunct database because I just entered raw wheat as an ingredient, which probably gave me a higher efficiency than I actually attained; my average is 80%).

JEFF/LATHE: is there a difference in the potential gravity for regular baking/bread white flour as compared to raw wheat? I'd think that a difference would be unavoidable given that the weight contains no husk material or germ. If different, I'd like to see it added to the ingredient database. Thanks.